12alpha-hydroxy-12beta-methyltigogenin and 12-methylene steroids derived therefrom



IZa-HYDROXY-lZfl-METHYLTIGOGENIN AND 12- METHYLENE STEROIDS DERIVEDTHEREFROM Luis E. Miramontes and Miguel AJRoniero, Mexico City, Mexico, assignors to G. D. Searle & Co., Chicago, 111., a' corporation of Delaware a No Drawing. Filed Sept. 30, '1959, Ser. No. 843,375

The present invention relates to a new group of 12- methyl steroids and, more particularly to 12a-hydroxy- IZB-methyItigogenin, a compound which can also be named as a 3B,l2a-dihydroxy-12B-methyl-5a,22u-spirostan and which has thes'tructural formula on. OH OCH;

This compound is an extremely valuable intermediate for I:

the preparation of IZ-methylene steroids.

The compound shown above is conveniently prepared from such readily available starting materials as hecogenin and its esters. An ester of hecogenin is treated with a methylmagnesium halide under Grignard conditions, typically in an aromatic hydrocarbon solvent such as benzene, toluene or xylene. The IZd-hydroxy-lZfi-methyltigogenin thus produced is conveniently converted to the 3-monoester by treatment with the appropriate alkanoic anhydride and pyridine.

Pseudomerization of 12u-hydroxy-IZfi-methyItigogenin or its esterbyheating with acetic anhydride at a temperature in the range of about 190 yields the SB-acyloxy- 12-methylene-5a-furostan-20(22)ene which on treatment with chromium trioxide in acetic acid is converted to the 3 acyloxy-12-methylene-l6-('y-methyl-fi-acetoxypentanoyloxy) 5on-P1'6gllfin-20-OI16. Some difiiculty is encountered in splitting of the 16-side chain when using such mild conditions as refluxingin aqueous acetic acid or treatment with alkaline aqueous acetone at room temperature. The reactiorr'ic'an be 'carriedoutby heating with aqueous alkaline acetone. However, it is preferred to carry out cleavage with alumina. For example, the 16-(' -methylc-acetoxypentanoyloxy) derivative canbe adsorbed on alumina and elution with a 1:1 mixture of benzene and hexane then yields the 3B-acyloxy-12-methylene-5a-pregn- 16-en-20-one; the unsplit ester is recovered from the column on elution with more'polar solvents. Treatment with alkaline hydrogen peroxide yields 3,8-hydroxy-12- methylene 16a,17a-epoxypregnan-20-one. This alcohol, its 3-monoesters and the corresponding oxo compound 2,954,375 Patented Sept. 27, 1960 derived therefrom by oxidation with chromic acid have a surprising physiological activity in that they are able to antagonize the sodium retention produced by aldosterone.

The 3,8 acyloxy-12 methylene-5a-pregn-16-en-20-ones can be hydrogenated by use ofpalladium catalyst to yield the 3fi-acyloxy-12methylene-Sa-pregnan-ZO-one usinga catalyst such as palladium. These esters are likewise antagonists of aldosterone.

This invention will appear in further detail from the details set forth in the examples but is not to be construed as limited thereby in scope. It will beapparent to those skilled in the art that numerous modifications of materials and methods can be adopted without departing from the invention. In these examples quantities are given in parts by weight.

Example 1 A solution of parts of 3-molar methyl magnesium bromide in benzeneis added slowly with stirring to a solution of 20 parts of anhydrous hecogenin acetate. The mixture is then refluxed for 8 hours. The excess Grignard reagent. is destroyed by carefully adding cold water at low temperature. Then a mixture of 50 parts of hydrochloric acid and SO'par'ts of water is added. The solution is heated-slightly to dissolve the precipitate and the organic layer is separated, washed with water to neutrality,

dried over anhydrous sodium sulfate, filtered, and evaporated to dryness. The residue is taken up in ethanol and a small amount of water is added to induce the crystallization of 35,120: dihydroxy 12p methyl-5a,22u-spirostan l2a-hydroxy-IZB-methyltigogenin) which is recovered by filtration and recrystallized from aqueous ethanol. The compound melts at about 205=-206 C. and has the specific rotation of about 4'0. 1

. Example 2 10 parts of 35,120; dihydroxy 12B methyl-50:22aspirostan is heated with- 20 parts of acetic anhydride in pyridine solution for 1' hour to yield 3B-acetoxy-12uhydroxy-l2fi-methyl-5a,22 c-spirostan (12a-hydroxy-125- niethyltigog'enin acetate) melting at about 228-22950 The specific rotation is about -42.8.

Example 3 A mixture of '25 parts of 3B,l2a-dihydroxy l2fl-methyl- 5oz,22o-Spi1'0Stan and 100 parts of acetic anhydride is heated for 6 hours at atemperature of 190 C. The mixture is then diluted with 100 parts of acetic acid and 23 parts of water and agitated for 30 minutes at a temperature of 40 C. After cooling to about 0 C. parts of 1,2-dichloroethane are added. In the course of 90 minutes a solution of 10.5 parts of chromic oxide in 16.5 parts of water .and 10.5 parts of acetic acid is added to the reaction mixture with stirring at a temperature of about 5-11 C. When the addition is completed,- the "solution is heated to room temperature and stirring is 3 rotation is about +50". The product has the structural epoxya-pregnane-3,20-dione thus obtained melts at about formula l64-l66 C. and has the specific rotation of about +138.

O-OO-CHg-CHr-CH-CHr-O-COCHI CHaC O O I Example 4 Example-8 A solution of Sfl-acetoxy-l2-methylene-16-('y-rnethyl-6- -A solution of 2 parts of 3fl acetoxy-12-methylene-5aacetoxypentanoyloxy)-5a-pregnan -one in a 1:1 mixture pregn-16-en-20-one in 23 parts of ethyl acetate is hyof benzene and hexane is chromatographed over alumina. drogenated over @1375 part of a 5% palladium onibar'ium There is thus obtained 3B-acetoxy-1Z-methylene-Sa-pregn- 20 sulfate catalyst. The solution is chromatografihed on 16-en-20-one melting at about 153-154" C. The specific alumina and the product is recrystallized from a mixrotation is about +190". The compound has the structure of 'chl'oroformand methanol to yield 3fi 'acetoxy'l2- tural formula methyIene-Sapregnan-ZO-Qne melting at about 97-98 C. The specific rotation is about +54. The compound has the structural formula H2O C0 CH3 H'zcll CO on CH:COO I 1!: Example 5 2 CHaCOO I 1 -A solution or 1 part or BB-acetOXy-I2 methylene-5a- H pregnan-16-en-20-one in 8 parts of chloroform is mixed What IS claimed 15: with 8 parts of methanol, 2 parts of 25% hydrogen 3B acewxy 12 methylene methyl peroxide and 026 part of sodium hydroxidein 1.25 parts 4 0 'acetoxypentanoyloxy) 'SwPTBgnaEQO'One' of water. The reaction mixture is allowed to stand for acetoxy 12 methylene Pregn 16 24 hours at room temperature. Acetic acid is added to neutralize the alkali and water is added to induce precipi- A compound of the S'tmcmral formula tation. The precipitate is recovered 'by filtration and dis- CH3 solved in chloroform. The solution is evaporated and I 2 CH3 .pregnan-ZO-One melting at about 206 208 C. The

the residue is recrystallized from a mixture of chloroform and methanol to yield SB-hydr'Q'Xy-IZ-methyIene-I 604,170:- epoxy-Sa-pregnanQO-one melting at about 9294 C. The specific rotation is about +105".

Example 6 5 A mixture of 10 parts of 3/3-hydroxy-12-methylene- 16a,17ot-epoxy-5aregnan-ZO-Qne is heated with 20 parts of acetic anhydride inpyridine solution for about 1 hour to yield 3e acetoxy --12 methylene-16a,l7a-epoxy-5awherein Z .is a member of the :class consisting of fispemfic rota/on is about +90 hydroxy methylene, ;9acetoxymethylene and the carbonyl Example 7 radical.

To a solution of 6.45 parts of 3B-hydroxy-l2-methylenee f hy methylene epoxy 16m,17a-epoxy-5a-pregnan-20-one and 160 parts of i n 'fi i- I 16 17 I 5 acetone are added with stirring and cooling 26.7 parts me Y en a epoxy a P of chromic oxide, 42 parts of concentrated sulfuric acid, 39 9 V V and 30 parts of water. Stirring is continued for 5 minutes 3fiact3toxy'12methy1ene-5WPTGgYIaH-ZO-OM- and water is added to precipitate the product which is I v collected by filtration and recrystallized from a mixture Refel'encesclted the-file of fills Patent of chloroform and methanol. 12methylene-16u,17aet a1. 49 Chem. Abst., 9'685-87 (1955,). 

3. A COMPOUND OF THE STRUCTURAL FORMULA 